FRIABLE
, a quality of bodies by which they are rendered tender and brittle, easily crumbled or reduced to powder between the fingers; their force of cohesion being such as easily exposes them to such solution. Such are pumice, and all calcined stones, burnt allum, &c.
It is supposed that Friability arises from hence, that the body consists wholly of dry parts irregularly combined, and which are readily separated, as having nothing unctuous or glutinous to bind them together.